Added hint about deleting operations

app/src/main/res/layout/fragment_operations.xml

@@ -17,6 +17,17 @@
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent" />
 
+    <TextView
+        android:id="@+id/tvHintOperation"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:padding="6dp"
+        android:text="@string/title_hint_operations"
+        android:textAppearance="@style/TextAppearance.AppCompat.Small"
+        android:textColor="?android:attr/textColorPrimary"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
     <androidx.recyclerview.widget.RecyclerView
         android:id="@+id/rvOperation"
         android:layout_width="0dp"
@@ -26,7 +37,7 @@
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+        app:layout_constraintTop_toBottomOf="@id/tvHintOperation" />
 
     <eu.faircode.email.ContentLoadingProgressBar
         android:id="@+id/pbWait"

app/src/main/res/values/strings.xml

@@ -489,6 +489,7 @@
     <string name="title_delete_operation">Delete operations with an error message?</string>
     <string name="title_delete_contacts">Delete all local contacts?</string>
     <string name="title_no_operations">No pending operations</string>
+    <string name="title_hint_operations">Deleting operations can result in disappearing messages and synchronization problems</string>
 
     <string name="title_folder_name">Folder name</string>
     <string name="title_display_name">Display name</string>